The present invention relates to apparatus and methodology for inserting an intraocular lenses (IOL) into an eye.
The human eye is susceptible to numerous disorders and diseases, a number of which attack the crystalline lens. For example, cataracts mar vision through cloudy or opaque discoloration of the lens of the eye. Cataracts often result in partial or complete blindness. A damaged crystalline lens can be removed and replaced with an intraocular lens, or IOL.
An IOL is implanted in the eye, for example, as a replacement for the natural crystalline lens after cataract surgery or to alter the optical properties of (i.e., provide vision correction to) an eye in which the natural lens remains. IOLs often include a disk-like optic typically including an optically clear lens. Many IOLs also include at least one flexible fixation member or haptic which extends radially outward from the optic and becomes affixed in the eye to secure the lens in position. Implantation of IOLs into the eye involves making an incision in the eye. To reduce trauma and to speed healing, it is advantageous to minimize the size the incision.
The optics may be constructed of rigid biocompatible materials such as polymethyl methacrylate (PMMA) or deformable materials such as silicone polymeric materials, acrylic polymeric materials, hydrogel polymeric materials, and the like. Deformable materials allow the IOL to be rolled or folded for insertion through a small incision into the eye. A substantial number of instruments have been proposed to aid in inserting such a foldable lens in the eye. In a popular apparatus, the optic is folded into a hard-shelled taco and pushed through an insertion tube, progressively compressing the IOL to fit through the incision.
The two primary IOL materials are silicone and acrylic. Silicone IOLs are more pliable and can be compressed to pass through smaller insertion tubes without unduly stressing the insertion tube or IOL, or requiring excessive push force which can violently expel the IOL from the cartridge. Acrylic lenses are indicated for some patients and are inserted in much the same way as silicone IOLs, although generally using larger insertion tubes with larger bore diameters to mitigate the problems caused by the lower flexibility of the acrylic. Because the insertion tubes are larger, the incision sizes are also necessarily larger.
In view of the foregoing, there is a continued need in the art for beneficial advancements in IOL insertion apparatus and methodology.